Answer
(a) The work that gravity does on the painter is -1750 J.
(b) The answer to part (a) does not depend on speed or acceleration.
Work Step by Step
(a) The force of gravity (directed straight down) makes an angle of $150^{\circ}$ with the painter's motion.
$W = mg~d~cos(150^{\circ})$
$W = (75.0~kg)(9.80~m/s^2)(2.75~m)~cos(150^{\circ})$
$W = -1750~J$
The work that gravity does on the painter is -1750 J.
(b) The answer to part (a) does not depend on speed or acceleration. The answer to part (a) depends on the change in the vertical position of the painter.
